I have developed a number of combustion chamber systems for spark-ignition linear engines in which the combustion chamber comprises, or is effectively divided into, a pre-combustion chamber and a main combustion chamber. Examples of such dual combustion chamber systems are disclosed within U.S. Pat. No. 4,759,318 which issued to me on Jul. 26, 1988, U.S. Pat. No. 4,665,868 which issued to me on May 19, 1987, U.S. Pat. No. 4,510,748 which issued to me on Apr. 16, 1985, and U.S. Pat. No. 4,365,471 which issued to me on Dec. 28, 1982. Ignition preferably originates in the pre-combustion chambers of such systems. Some unburned fuel and air in the pre-combustion chamber is forced ahead of a flame jet into the main combustion chamber. Upon arrival, the flame jet triggers combustion of a compressed fuel and air mixture in the main combustion chamber.
When a combustion cycle is initiated, both the pre-combustion chamber and the main combustion chamber are charged with a mixture of fuel and air, and the pre-established mixture within the pre-combustion chamber is then ignited. Ideally, a generated flame front propagates through the pre-combustion chamber so as to push unburned fuel and air in front of it toward the main combustion chamber, thereby further mixing and compressing the fuel and air in the main combustion chamber. A check valve effectively separates the pre-combustion and main combustion chambers so as to permit the unburned fuel and air and the flame front to enter the main combustion chamber from the pre-combustion chamber but to limit any reverse flow of combustion products from the main combustion chamber back into the pre-combustion chamber. As the flame front enters the main combustion chamber, it ignites the compressed fuel and air mixture disposed within the main combustion chamber. This process elevates the combustion pressure within the main combustion chamber leading to a more efficient combustion within the main combustion chamber. Accordingly, such higher pressures can more effectively and powerfully perform useful work, such as driving of fasteners with combustion-powered fastener-driving tools.
It is also desirable or even necessary that, in connection with the use of certain combustion-powered fastener-driving tools, the tools be readily portable, relatively light in weight, and relatively small in size. Accordingly, it is desirable to achieve the aforenoted combustion process wherein the combustion pressure within the main combustion chamber is substantially elevated so as to lead to more efficient combustion within the main combustion chamber whereby such higher pressures can more effectively and more powerfully perform useful work, such as, for example, the driving of fasteners through and out from combustion-powered fastener-driving tools, and yet the tools must be readily portable, relatively light in weight, and relatively small in size.
A need therefore exists in the art for a new and improved combustion-powered tool which has incorporated therein suitable structure which is capable of readily attaining enhanced energy output levels such that the resulting energy derived from the combustion-powered tool enables the combustion-powered tool to be used in connection with the installation of fasteners into substrates or workpieces, and yet the internal structure incorporated within the tool for achieving the desired energy output levels is itself compact so as to in turn render the overall tool readily portable, relatively light in weight, and relatively small in size.